DETERMINATION OF TRACE LEVELS OF DIAZINON AND PROPETAMPHOS IN WATER AND SEWAGE BY SOLID-PHASE EXTRACTION

An analytical method is described for the determination of the organophosphorus pesticides diazinon and propetamphos in water and in sewage, at levels ranging from 0.01-1.0 mg/L. The method involves solid phase extraction using C-18 Bond Elut cartridges, elution with ether, and solvent change to hexane. Quantification of the pesticide is by temperature programmed capillary gas chromatography using a nitrogen-phosphorus detector. Recoveries of diazinon are between 98-102% from water and between 70-80% from activated sludge biomass. These results are compared with a more polar organophosphate, propetamphos, for which the recovery from both water and biomass is close to 100%.